monoamine n : a molecule containing one amine group (especially one that is a neurotransmitter)

English

Etymology

From mono- + amine.

Pronunciation

/mɒnəʊˈeɪmiːn/

Noun

1. In the context of "chemistry|biochemistry": Any compound having a single amino functional group, especially a neurotransmitter.
   • 2001: The first effective drugs used to treat clinical depression were compounds that act by enhancing the activity of chemicals known as monoamines in the brain. — Leslie Iversen, Drugs: A Very Short Introduction (Oxford 2001, p. 55)

Monoamine neurotransmitters are neurotransmitters and neuromodulators that contain one amino group that is connected to an aromatic ring by a two-carbon chain (-CH2-CH2-). All monoamines are derived from aromatic amino acids like phenylalanine, tyrosine, tryptophan, and the thyroid hormones by the action of aromatic amino acid decarboxylase enzymes.

Examples

• Catecholamines:
  • Dopamine (DA)
  • Norepinephrine (NE) (noradrenaline, NA)
  • Epinephrine (Epi) (adrenaline)
• Melatonin
• Histamine
• Serotonin (5-HT)
• Thyronamines, a new group of compounds derived from thyroid hormones
• Trace amines:
  • β-Phenylethylamine (PEA, β-PEA)
  • Tyramine
  • Tryptamine
  • Octopamine
  • 3-iodothyronamine

Specific transporter proteins called monoamine transporters exist that transport monoamines in or out of a cell. These are the dopamine transporter (DAT), serotonin transporter (SERT), and the norepinephrine transporter (NET) in the outer cell membrane and the vesicular monoamine transporter (VMAT1 and VMAT2) in the membrane of intracellular vesicles.

Monoamine oxidase is an enzyme that breaks down monoamine neurotransmitters after they have been released into the synapse.

See also

• Monoamine oxidase
• Monoamine transporter
• Neurotransmitter
• Monoamine Hypothesis

External links